PHP get_component_directory函数代码示例

/**
 * Returns detailed function information
 * @param string|object $function name of external function or record from external_function
 * @param int $strictness IGNORE_MISSING means compatible mode, false returned if record not found, debug message if more found;
 *                        MUST_EXIST means throw exception if no record or multiple records found
 * @return object description or false if not found or exception thrown
 */
function external_function_info($function, $strictness=MUST_EXIST) {
    global $DB, $CFG;

    if (!is_object($function)) {
        if (!$function = $DB->get_record('external_functions', array('name'=>$function), '*', $strictness)) {
            return false;
        }
    }

    //first find and include the ext implementation class
    $function->classpath = empty($function->classpath) ? get_component_directory($function->component).'/externallib.php' : $CFG->dirroot.'/'.$function->classpath;
    if (!file_exists($function->classpath)) {
        throw new coding_exception('Can not find file with external function implementation');
    }
    require_once($function->classpath);

    $function->parameters_method = $function->methodname.'_parameters';
    $function->returns_method    = $function->methodname.'_returns';

    // make sure the implementaion class is ok
    if (!method_exists($function->classname, $function->methodname)) {
        throw new coding_exception('Missing implementation method of '.$function->classname.'::'.$function->methodname);
    }
    if (!method_exists($function->classname, $function->parameters_method)) {
        throw new coding_exception('Missing parameters description');
    }
    if (!method_exists($function->classname, $function->returns_method)) {
        throw new coding_exception('Missing returned values description');
    }

    // fetch the parameters description
    $function->parameters_desc = call_user_func(array($function->classname, $function->parameters_method));
    if (!($function->parameters_desc instanceof external_function_parameters)) {
        throw new coding_exception('Invalid parameters description');
    }

    // fetch the return values description
    $function->returns_desc = call_user_func(array($function->classname, $function->returns_method));
    // null means void result or result is ignored
    if (!is_null($function->returns_desc) and !($function->returns_desc instanceof external_description)) {
        throw new coding_exception('Invalid return description');
    }

    //now get the function description
    //TODO: use localised lang pack descriptions, it would be nice to have
    //      easy to understand descriptions in admin UI,
    //      on the other hand this is still a bit in a flux and we need to find some new naming
    //      conventions for these descriptions in lang packs
    $function->description = null;
    $servicesfile = get_component_directory($function->component).'/db/services.php';
    if (file_exists($servicesfile)) {
        $functions = null;
        include($servicesfile);
        if (isset($functions[$function->name]['description'])) {
            $function->description = $functions[$function->name]['description'];
        }
    }

    return $function;
}

/**
 * Adds a specified user to a group
 *
 * @param mixed $grouporid  The group id or group object
 * @param mixed $userorid   The user id or user object
 * @param string $component Optional component name e.g. 'enrol_imsenterprise'
 * @param int $itemid Optional itemid associated with component
 * @return bool True if user added successfully or the user is already a
 * member of the group, false otherwise.
 */
function groups_add_member($grouporid, $userorid, $component = null, $itemid = 0)
{
    global $DB;
    if (is_object($userorid)) {
        $userid = $userorid->id;
        $user = $userorid;
    } else {
        $userid = $userorid;
        $user = $DB->get_record('user', array('id' => $userid), '*', MUST_EXIST);
    }
    if (is_object($grouporid)) {
        $groupid = $grouporid->id;
        $group = $grouporid;
    } else {
        $groupid = $grouporid;
        $group = $DB->get_record('groups', array('id' => $groupid), '*', MUST_EXIST);
    }
    //check if the user a participant of the group course
    if (!is_enrolled(context_course::instance($group->courseid), $userid)) {
        return false;
    }
    if (groups_is_member($groupid, $userid)) {
        return true;
    }
    $member = new stdClass();
    $member->groupid = $groupid;
    $member->userid = $userid;
    $member->timeadded = time();
    $member->component = '';
    $member->itemid = 0;
    // Check the component exists if specified
    if (!empty($component)) {
        $dir = get_component_directory($component);
        if ($dir && is_dir($dir)) {
            // Component exists and can be used
            $member->component = $component;
            $member->itemid = $itemid;
        } else {
            throw new coding_exception('Invalid call to groups_add_member(). An invalid component was specified');
        }
    }
    if ($itemid !== 0 && empty($member->component)) {
        // An itemid can only be specified if a valid component was found
        throw new coding_exception('Invalid call to groups_add_member(). A component must be specified if an itemid is given');
    }
    $DB->insert_record('groups_members', $member);
    //update group info
    $DB->set_field('groups', 'timemodified', $member->timeadded, array('id' => $groupid));
    //trigger groups events
    $eventdata = new stdClass();
    $eventdata->groupid = $groupid;
    $eventdata->userid = $userid;
    $eventdata->component = $member->component;
    $eventdata->itemid = $member->itemid;
    events_trigger('groups_member_added', $eventdata);
    return true;
}

/**
 * Loads the events definitions for the component (from file). If no
 * events are defined for the component, we simply return an empty array.
 *
 * INTERNAL - to be used from eventslib only
 *
 * @global object
 * @param string $component examples: 'moodle', 'mod/forum', 'block/quiz_results'
 * @return array of capabilities or empty array if not exists
 */
function events_load_def($component)
{
    $defpath = get_component_directory($component) . '/db/events.php';
    $handlers = array();
    if (file_exists($defpath)) {
        require $defpath;
    }
    return $handlers;
}

/**
 * Loads the events definitions for the component (from file). If no
 * events are defined for the component, we simply return an empty array.
 *
 * INTERNAL - to be used from eventslib only
 *
 * @param string $component examples: 'moodle', 'mod_forum', 'block_quiz_results'
 * @return array of capabilities or empty array if not exists
 */
function events_load_def($component)
{
    global $CFG;
    if ($component === 'unittest') {
        $defpath = $CFG->dirroot . '/lib/simpletest/fixtures/events.php';
    } else {
        $defpath = get_component_directory($component) . '/db/events.php';
    }
    $handlers = array();
    if (file_exists($defpath)) {
        require $defpath;
    }
    // make sure the definitions are valid and complete; tell devs what is wrong
    foreach ($handlers as $eventname => $handler) {
        if ($eventname === 'reset') {
            debugging("'reset' can not be used as event name.");
            unset($handlers['reset']);
            continue;
        }
        if (!is_array($handler)) {
            debugging("Handler of '{$eventname}' must be specified as array'");
            unset($handlers[$eventname]);
            continue;
        }
        if (!isset($handler['handlerfile'])) {
            debugging("Handler of '{$eventname}' must include 'handlerfile' key'");
            unset($handlers[$eventname]);
            continue;
        }
        if (!isset($handler['handlerfunction'])) {
            debugging("Handler of '{$eventname}' must include 'handlerfunction' key'");
            unset($handlers[$eventname]);
            continue;
        }
        if (!isset($handler['schedule'])) {
            $handler['schedule'] = 'instant';
        }
        if ($handler['schedule'] !== 'instant' and $handler['schedule'] !== 'cron') {
            debugging("Handler of '{$eventname}' must include valid 'schedule' type (instant or cron)'");
            unset($handlers[$eventname]);
            continue;
        }
        if (!isset($handler['internal'])) {
            $handler['internal'] = 1;
        }
        $handlers[$eventname] = $handler;
    }
    return $handlers;
}

 /**
  * Return user information including profile picture + basic site information
  * Note:
  * - no capability checking because we return just known information by logged user
  * @param array $serviceshortnames of service shortnames - the functions of these services will be returned
  * @return array
  */
 public function get_site_info($serviceshortnames = array())
 {
     global $USER, $SITE, $CFG;
     $params = self::validate_parameters(self::get_site_info_parameters(), array('serviceshortnames' => $serviceshortnames));
     $profileimageurl = moodle_url::make_pluginfile_url(get_context_instance(CONTEXT_USER, $USER->id)->id, 'user', 'icon', NULL, '/', 'f1');
     require_once $CFG->dirroot . "/webservice/lib.php";
     $webservice = new webservice();
     //If no service listed always return the mobile one by default
     if (empty($params['serviceshortnames']) and $CFG->enablewebservices) {
         $mobileservice = $webservice->get_external_service_by_shortname(MOODLE_OFFICIAL_MOBILE_SERVICE);
         if ($mobileservice->enabled) {
             $params['serviceshortnames'] = array(MOODLE_OFFICIAL_MOBILE_SERVICE);
             //return mobile service by default
         }
     }
     //retrieve the functions related to the services
     $functions = $webservice->get_external_functions_by_enabled_services($params['serviceshortnames']);
     //built up the returned values of the list of functions
     $componentversions = array();
     $avalaiblefunctions = array();
     foreach ($functions as $function) {
         $functioninfo = array();
         $functioninfo['name'] = $function->name;
         if ($function->component == 'moodle') {
             $version = $CFG->version;
             //moodle version
         } else {
             $versionpath = get_component_directory($function->component) . '/version.php';
             if (is_readable($versionpath)) {
                 //we store the component version once retrieved (so we don't load twice the version.php)
                 if (!isset($componentversions[$function->component])) {
                     include $versionpath;
                     $componentversions[$function->component] = $plugin->version;
                     $version = $plugin->version;
                 } else {
                     $version = $componentversions[$function->component];
                 }
             } else {
                 //function component should always have a version.php,
                 //otherwise the function should have been described with component => 'moodle'
                 throw new moodle_exception('missingversionfile', 'webservice', '', $function->component);
             }
         }
         $functioninfo['version'] = $version;
         $avalaiblefunctions[] = $functioninfo;
     }
     return array('sitename' => $SITE->fullname, 'siteurl' => $CFG->wwwroot, 'username' => $USER->username, 'firstname' => $USER->firstname, 'lastname' => $USER->lastname, 'fullname' => fullname($USER), 'userid' => $USER->id, 'userpictureurl' => $profileimageurl->out(false), 'functions' => $avalaiblefunctions);
 }

/**
 * Loads the task definitions for the component (from file). If no
 * tasks are defined for the component, we simply return an empty array.
 * @param $component - examples: 'moodle', 'mod_forum', 'block_quiz_results'
 * @return array of tasks or empty array if not exists
 *
 * INTERNAL - to be used from cronlib only
 */
function elis_tasks_load_def($component)
{
    global $CFG;
    if ($component == 'moodle') {
        $defpath = $CFG->libdir . '/db/tasks.php';
        //} else if ($component == 'unittest') {
        //    $defpath = $CFG->libdir.'/simpletest/fixtures/tasks.php';
    } else {
        $defpath = get_component_directory($component) . '/db/tasks.php';
        //error_log("/local/eliscore/lib/tasklib.php::elis_tasks_load_def('{$component}') looking for: {$defpath}");
    }
    $tasks = array();
    if (file_exists($defpath)) {
        require $defpath;
    }
    return $tasks;
}

 /**
  * Determine the module metadata for all moodle YUI modules.
  *
  * This works through all modules capable of serving YUI modules, and attempts to get
  * metadata for each of those modules.
  *
  * @return Array of module metadata
  */
 private function get_moodle_metadata()
 {
     $moodlemodules = array();
     // Core isn't a plugin type or subsystem - handle it seperately.
     if ($module = $this->get_moodle_path_metadata(get_component_directory('core'))) {
         $moodlemodules = array_merge($moodlemodules, $module);
     }
     // Handle other core subsystems.
     $subsystems = get_core_subsystems();
     foreach ($subsystems as $subsystem => $path) {
         if (is_null($path)) {
             continue;
         }
         $path = get_component_directory($subsystem);
         if ($module = $this->get_moodle_path_metadata($path)) {
             $moodlemodules = array_merge($moodlemodules, $module);
         }
     }
     // And finally the plugins.
     $plugintypes = get_plugin_types();
     foreach ($plugintypes as $plugintype => $pathroot) {
         $pluginlist = get_plugin_list($plugintype);
         foreach ($pluginlist as $plugin => $path) {
             if ($module = $this->get_moodle_path_metadata($path)) {
                 $moodlemodules = array_merge($moodlemodules, $module);
             }
         }
     }
     return $moodlemodules;
 }

 /**
  * Find out if JS module present and return details.
  * @param string $component name of component in frankenstyle, ex: core_group, mod_forum
  * @return array description of module or null if not found
  */
 protected function find_module($component)
 {
     global $CFG;
     $module = null;
     if (strpos($component, 'core_') === 0) {
         // must be some core stuff - list here is not complete, this is just the stuff used from multiple places
         // so that we do nto have to repeat the definition of these modules over and over again
         switch ($component) {
             case 'core_filepicker':
                 $module = array('name' => 'core_filepicker', 'fullpath' => '/repository/filepicker.js', 'requires' => array('base', 'node', 'node-event-simulate', 'json', 'async-queue', 'io', 'yui2-button', 'yui2-container', 'yui2-layout', 'yui2-menu', 'yui2-treeview', 'yui2-dragdrop', 'yui2-cookie'), 'strings' => array(array('add', 'repository'), array('back', 'repository'), array('cancel', 'moodle'), array('close', 'repository'), array('cleancache', 'repository'), array('copying', 'repository'), array('date', 'repository'), array('downloadsucc', 'repository'), array('emptylist', 'repository'), array('error', 'repository'), array('federatedsearch', 'repository'), array('filenotnull', 'repository'), array('getfile', 'repository'), array('help', 'moodle'), array('iconview', 'repository'), array('invalidjson', 'repository'), array('linkexternal', 'repository'), array('listview', 'repository'), array('loading', 'repository'), array('login', 'repository'), array('logout', 'repository'), array('noenter', 'repository'), array('noresult', 'repository'), array('manageurl', 'repository'), array('popup', 'repository'), array('preview', 'repository'), array('refresh', 'repository'), array('save', 'repository'), array('saveas', 'repository'), array('saved', 'repository'), array('saving', 'repository'), array('search', 'repository'), array('searching', 'repository'), array('size', 'repository'), array('submit', 'repository'), array('sync', 'repository'), array('title', 'repository'), array('upload', 'repository'), array('uploading', 'repository'), array('xhtmlerror', 'repository'), array('cancel'), array('chooselicense', 'repository'), array('author', 'repository'), array('ok', 'moodle'), array('error', 'moodle'), array('info', 'moodle'), array('norepositoriesavailable', 'repository'), array('norepositoriesexternalavailable', 'repository'), array('nofilesattached', 'repository'), array('filepicker', 'repository'), array('nofilesavailable', 'repository'), array('overwrite', 'repository'), array('renameto', 'repository'), array('fileexists', 'repository'), array('fileexistsdialogheader', 'repository'), array('fileexistsdialog_editor', 'repository'), array('fileexistsdialog_filemanager', 'repository')));
                 break;
             case 'core_comment':
                 $module = array('name' => 'core_comment', 'fullpath' => '/comment/comment.js', 'requires' => array('base', 'io', 'node', 'json', 'yui2-animation', 'overlay'), 'strings' => array(array('confirmdeletecomments', 'admin'), array('yes', 'moodle'), array('no', 'moodle')));
                 break;
             case 'core_role':
                 $module = array('name' => 'core_role', 'fullpath' => '/admin/roles/module.js', 'requires' => array('node', 'cookie'));
                 break;
             case 'core_completion':
                 $module = array('name' => 'core_completion', 'fullpath' => '/course/completion.js');
                 break;
             case 'core_dock':
                 $module = array('name' => 'core_dock', 'fullpath' => '/blocks/dock.js', 'requires' => array('base', 'node', 'event-custom', 'event-mouseenter', 'event-resize'), 'strings' => array(array('addtodock', 'block'), array('undockitem', 'block'), array('undockall', 'block'), array('thisdirectionvertical', 'langconfig')));
                 break;
             case 'core_message':
                 $module = array('name' => 'core_message', 'requires' => array('base', 'node', 'event', 'node-event-simulate'), 'fullpath' => '/message/module.js');
                 break;
             case 'core_group':
                 $module = array('name' => 'core_group', 'fullpath' => '/group/module.js', 'requires' => array('node', 'overlay', 'event-mouseenter'));
                 break;
             case 'core_question_engine':
                 $module = array('name' => 'core_question_engine', 'fullpath' => '/question/qengine.js', 'requires' => array('node', 'event'));
                 break;
             case 'core_rating':
                 $module = array('name' => 'core_rating', 'fullpath' => '/rating/module.js', 'requires' => array('node', 'event', 'overlay', 'io', 'json'));
                 break;
             case 'core_filetree':
                 $module = array('name' => 'core_filetree', 'fullpath' => '/files/module.js', 'requires' => array('node', 'event', 'overlay', 'io', 'json', 'yui2-treeview'));
                 break;
         }
     } else {
         if ($dir = get_component_directory($component)) {
             if (file_exists("{$dir}/module.js")) {
                 if (strpos($dir, $CFG->dirroot . '/') === 0) {
                     $dir = substr($dir, strlen($CFG->dirroot));
                     $module = array('name' => $component, 'fullpath' => "{$dir}/module.js", 'requires' => array());
                 }
             }
         }
     }
     return $module;
 }

/**
 * Loads the messages definitions for a component from file
 *
 * If no messages are defined for the component, return an empty array.
 * This is an internal function used within messagelib.php
 *
 * @see message_update_providers()
 * @see message_update_processors()
 * @param string $component A moodle component like 'moodle', 'mod_forum', 'block_quiz_results'
 * @return array An array of message providers or empty array if not exists
 */
function message_get_providers_from_file($component) {
    $defpath = get_component_directory($component).'/db/messages.php';

    $messageproviders = array();

    if (file_exists($defpath)) {
        require($defpath);
    }

    foreach ($messageproviders as $name => $messageprovider) {   // Fix up missing values if required
        if (empty($messageprovider['capability'])) {
            $messageproviders[$name]['capability'] = NULL;
        }
        if (empty($messageprovider['defaults'])) {
            $messageproviders[$name]['defaults'] = array();
        }
    }

    return $messageproviders;
}

                 } else {
                     $birecord = null;
                 }
                 $filefunction = $component . '_pluginfile';
                 if (function_exists($filefunction)) {
                     // if the function exists, it must send the file and terminate. Whatever it returns leads to "not found"
                     $filefunction($course, $birecord, $context, $filearea, $args, $forcedownload);
                 }
                 send_file_not_found();
             } else {
                 if (strpos($component, '_') === false) {
                     // all core subsystems have to be specified above, no more guessing here!
                     send_file_not_found();
                 } else {
                     // try to serve general plugin file in arbitrary context
                     $dir = get_component_directory($component);
                     if (!file_exists("{$dir}/lib.php")) {
                         send_file_not_found();
                     }
                     include_once "{$dir}/lib.php";
                     $filefunction = $component . '_pluginfile';
                     if (function_exists($filefunction)) {
                         // if the function exists, it must send the file and terminate. Whatever it returns leads to "not found"
                         $filefunction($course, $cm, $context, $filearea, $args, $forcedownload);
                     }
                     send_file_not_found();
                 }
             }
         }
     }
 }

    /**
     * Return user information including profile picture + basic site information
     * Note:
     * - no capability checking because we return only known information about logged user
     *
     * @param array $serviceshortnames - DEPRECATED PARAMETER - values will be ignored -
     * it was an original design error, we keep for backward compatibility.
     * @return array site info
     * @since Moodle 2.2
     */
    public static function get_site_info($serviceshortnames = array()) {
        global $USER, $SITE, $CFG, $DB;

        $params = self::validate_parameters(self::get_site_info_parameters(),
                      array('serviceshortnames'=>$serviceshortnames));

        $profileimageurl = moodle_url::make_pluginfile_url(
                context_user::instance($USER->id)->id, 'user', 'icon', null, '/', 'f1');

        // Site information.
        $siteinfo =  array(
            'sitename' => $SITE->fullname,
            'siteurl' => $CFG->wwwroot,
            'username' => $USER->username,
            'firstname' => $USER->firstname,
            'lastname' => $USER->lastname,
            'fullname' => fullname($USER),
            'userid' => $USER->id,
            'userpictureurl' => $profileimageurl->out(false)
        );

        // Retrieve the service and functions from the web service linked to the token
        // If you call this function directly from external (not a web service call),
        // then it will still return site info without information about a service
        // Note: wsusername/wspassword ws authentication is not supported.
        $functions = array();
        if ($CFG->enablewebservices) { // No need to check token if web service are disabled and not a ws call.
            $token = optional_param('wstoken', '', PARAM_ALPHANUM);

            if (!empty($token)) { // No need to run if not a ws call.
                // Retrieve service shortname.
                $servicesql = 'SELECT s.*
                               FROM {external_services} s, {external_tokens} t
                               WHERE t.externalserviceid = s.id AND token = ? AND t.userid = ? AND s.enabled = 1';
                $service = $DB->get_record_sql($servicesql, array($token, $USER->id));

                $siteinfo['downloadfiles'] = $service->downloadfiles;

                if (!empty($service)) {
                    // Return the release and version number for web service users only.
                    $siteinfo['release'] = $CFG->release;
                    $siteinfo['version'] = $CFG->version;
                    // Retrieve the functions.
                    $functionssql = "SELECT f.*
                            FROM {external_functions} f, {external_services_functions} sf
                            WHERE f.name = sf.functionname AND sf.externalserviceid = ?";
                    $functions = $DB->get_records_sql($functionssql, array($service->id));
                } else {
                    throw new coding_exception('No service found in get_site_info: something is buggy, \
                                                it should have fail at the ws server authentication layer.');
                }
            }
        }

        // Build up the returned values of the list of functions.
        $componentversions = array();
        $availablefunctions = array();
        foreach ($functions as $function) {
            $functioninfo = array();
            $functioninfo['name'] = $function->name;
            if ($function->component == 'moodle' || $function->component == 'core') {
                $version = $CFG->version; // Moodle version.
            } else {
                $versionpath = get_component_directory($function->component).'/version.php';
                if (is_readable($versionpath)) {
                    // We store the component version once retrieved (so we don't load twice the version.php).
                    if (!isset($componentversions[$function->component])) {
                        include($versionpath);
                        $componentversions[$function->component] = $plugin->version;
                        $version = $plugin->version;
                    } else {
                        $version = $componentversions[$function->component];
                    }
                } else {
                    // Function component should always have a version.php,
                    // otherwise the function should have been described with component => 'moodle'.
                    throw new moodle_exception('missingversionfile', 'webservice', '', $function->component);
                }
            }
            $functioninfo['version'] = $version;
            $availablefunctions[] = $functioninfo;
        }

        $siteinfo['functions'] = $availablefunctions;

        return $siteinfo;
    }

try {
    $autologinguest = true;
    $setwantsurltome = true;
    $preventredirect = true;
    require_login($course, $autologinguest, $cm, $setwantsurltome, $preventredirect);
} catch (Exception $e) {
    if (isguestuser()) {
        rss_error('rsserrorguest');
    } else {
        rss_error('rsserrorauth');
    }
}

// Work out which component in Moodle we want (from the frankenstyle name)
$componentdir = get_component_directory($componentname);
list($type, $plugin) = normalize_component($componentname);


// Call the component to check/update the feed and tell us the path to the cached file
$pathname = null;

if (file_exists($componentdir)) {
    require_once("$componentdir/rsslib.php");
    $functionname = $plugin.'_rss_get_feed';

    if (function_exists($functionname)) {
        // $pathname will be null if there was a problem (eg user doesn't have the necessary capabilities)
        // NOTE:the component providing the feed must do its own capability checks and security
        $pathname = $functionname($context, $args);
    }

/**
* Function to require any potential callback files, throwing exceptions
* if an issue occurs.
*
* @param string $callbackfile This is the location of the callback file '/mod/forum/locallib.php'
* @param string $class Name of the class containing the callback functions
* activity components should ALWAYS use their name_portfolio_caller
* other locations must use something unique
*/
function portfolio_include_callback_file($callbackfile, $class = null) {
    global $CFG;
    require_once($CFG->libdir . '/adminlib.php');

    // Get the last occurrence of '/' in the file path.
    $pos = strrpos($callbackfile, '/');
    // Get rid of the first slash (if it exists).
    $callbackfile = ltrim($callbackfile, '/');
    // Get a list of valid plugin types.
    $plugintypes = get_plugin_types(false);
    // Assume it is not valid for now.
    $isvalid = false;
    // Go through the plugin types.
    foreach ($plugintypes as $type => $path) {
        if (strrpos($callbackfile, $path) === 0) {
            // Found the plugin type.
            $isvalid = true;
            $plugintype = $type;
            $pluginpath = $path;
        }
    }
    // Throw exception if not a valid component.
    if (!$isvalid) {
        throw new coding_exception('Somehow a non-valid plugin path was passed, could be a hackz0r attempt, exiting.');
    }
    // Keep record of the filename.
    $filename = substr($callbackfile, $pos);
    // Remove the file name.
    $component = trim(substr($callbackfile, 0, $pos), '/');
    // Replace the path with the type.
    $component = str_replace($pluginpath, $plugintype, $component);
    // Ok, replace '/' with '_'.
    $component = str_replace('/', '_', $component);
    // Check that it is a valid component.
    if (!get_component_version($component)) {
        throw new portfolio_button_exception('nocallbackcomponent', 'portfolio', '', $component);
    }

    // Obtain the component's location.
    if (!$componentloc = get_component_directory($component)) {
        throw new portfolio_button_exception('nocallbackcomponent', 'portfolio', '', $component);
    }

    // Check if the filename does not meet any of the expected names.
    if (($filename != 'locallib.php') && ($filename != 'portfoliolib.php') && ($filename != 'portfolio_callback.php')) {
        debugging('Please standardise your plugin by keeping your portfolio callback functionality in the file locallib.php.', DEBUG_DEVELOPER);
    }

    // Throw error if file does not exist.
    if (!file_exists($componentloc . '/' . $filename)) {
        throw new portfolio_button_exception('nocallbackfile', 'portfolio', '', $callbackfile);
    }

    require_once($componentloc . '/' . $filename);

    if (!is_null($class) && !class_exists($class)) {
        throw new portfolio_button_exception('nocallbackclass', 'portfolio', '', $class);
    }
}

/**
 * Called by pluginfile.php to serve files related to the 'question' core
 * component and for files belonging to qtypes.
 *
 * For files that relate to questions in a question_attempt, then we delegate to
 * a function in the component that owns the attempt (for example in the quiz,
 * or in core question preview) to get necessary inforation.
 *
 * (Note that, at the moment, all question file areas relate to questions in
 * attempts, so the If at the start of the last paragraph is always true.)
 *
 * Does not return, either calls send_file_not_found(); or serves the file.
 *
 * @package  core_question
 * @category files
 * @param stdClass $course course settings object
 * @param stdClass $context context object
 * @param string $component the name of the component we are serving files for.
 * @param string $filearea the name of the file area.
 * @param array $args the remaining bits of the file path.
 * @param bool $forcedownload whether the user must be forced to download the file.
 * @param array $options additional options affecting the file serving
 */
function question_pluginfile($course, $context, $component, $filearea, $args, $forcedownload, array $options = array())
{
    global $DB, $CFG;
    if ($filearea === 'questiontext_preview') {
        $component = array_shift($args);
        $questionid = array_shift($args);
        component_callback($component, 'questiontext_preview_pluginfile', array($context, $questionid, $args, $forcedownload, $options));
        send_file_not_found();
    }
    if ($filearea === 'export') {
        list($context, $course, $cm) = get_context_info_array($context->id);
        require_login($course, false, $cm);
        require_once $CFG->dirroot . '/question/editlib.php';
        $contexts = new question_edit_contexts($context);
        // check export capability
        $contexts->require_one_edit_tab_cap('export');
        $category_id = (int) array_shift($args);
        $format = array_shift($args);
        $cattofile = array_shift($args);
        $contexttofile = array_shift($args);
        $filename = array_shift($args);
        // load parent class for import/export
        require_once $CFG->dirroot . '/question/format.php';
        require_once $CFG->dirroot . '/question/editlib.php';
        require_once $CFG->dirroot . '/question/format/' . $format . '/format.php';
        $classname = 'qformat_' . $format;
        if (!class_exists($classname)) {
            send_file_not_found();
        }
        $qformat = new $classname();
        if (!($category = $DB->get_record('question_categories', array('id' => $category_id)))) {
            send_file_not_found();
        }
        $qformat->setCategory($category);
        $qformat->setContexts($contexts->having_one_edit_tab_cap('export'));
        $qformat->setCourse($course);
        if ($cattofile == 'withcategories') {
            $qformat->setCattofile(true);
        } else {
            $qformat->setCattofile(false);
        }
        if ($contexttofile == 'withcontexts') {
            $qformat->setContexttofile(true);
        } else {
            $qformat->setContexttofile(false);
        }
        if (!$qformat->exportpreprocess()) {
            send_file_not_found();
            print_error('exporterror', 'question', $thispageurl->out());
        }
        // export data to moodle file pool
        if (!($content = $qformat->exportprocess(true))) {
            send_file_not_found();
        }
        send_file($content, $filename, 0, 0, true, true, $qformat->mime_type());
    }
    $qubaid = (int) array_shift($args);
    $slot = (int) array_shift($args);
    $module = $DB->get_field('question_usages', 'component', array('id' => $qubaid));
    if ($module === 'core_question_preview') {
        require_once $CFG->dirroot . '/question/previewlib.php';
        return question_preview_question_pluginfile($course, $context, $component, $filearea, $qubaid, $slot, $args, $forcedownload, $options);
    } else {
        $dir = get_component_directory($module);
        if (!file_exists("{$dir}/lib.php")) {
            send_file_not_found();
        }
        include_once "{$dir}/lib.php";
        $filefunction = $module . '_question_pluginfile';
        if (function_exists($filefunction)) {
            $filefunction($course, $context, $component, $filearea, $qubaid, $slot, $args, $forcedownload, $options);
        }
        // Okay, we're here so lets check for function without 'mod_'.
        if (strpos($module, 'mod_') === 0) {
            $filefunctionold = substr($module, 4) . '_question_pluginfile';
            if (function_exists($filefunctionold)) {
                $filefunctionold($course, $context, $component, $filearea, $qubaid, $slot, $args, $forcedownload, $options);
//.........这里部分代码省略.........

/**
 * Web service discovery function used during install and upgrade.
 * @param string $component name of component (moodle, mod_assignment, etc.)
 * @return void
 */
function external_update_descriptions($component)
{
    global $DB;
    $defpath = get_component_directory($component) . '/db/services.php';
    if (!file_exists($defpath)) {
        external_delete_descriptions($component);
        return;
    }
    // load new info
    $functions = array();
    $services = array();
    include $defpath;
    // update all function fist
    $dbfunctions = $DB->get_records('external_functions', array('component' => $component));
    foreach ($dbfunctions as $dbfunction) {
        if (empty($functions[$dbfunction->name])) {
            $DB->delete_records('external_functions', array('id' => $dbfunction->id));
            // do not delete functions from external_services_functions, beacuse
            // we want to notify admins when functions used in custom services disappear
            //TODO: this looks wrong, we have to delete it eventually (skodak)
            continue;
        }
        $function = $functions[$dbfunction->name];
        unset($functions[$dbfunction->name]);
        $function['classpath'] = empty($function['classpath']) ? null : $function['classpath'];
        $update = false;
        if ($dbfunction->classname != $function['classname']) {
            $dbfunction->classname = $function['classname'];
            $update = true;
        }
        if ($dbfunction->methodname != $function['methodname']) {
            $dbfunction->methodname = $function['methodname'];
            $update = true;
        }
        if ($dbfunction->classpath != $function['classpath']) {
            $dbfunction->classpath = $function['classpath'];
            $update = true;
        }
        $functioncapabilities = key_exists('capabilities', $function) ? $function['capabilities'] : '';
        if ($dbfunction->capabilities != $functioncapabilities) {
            $dbfunction->capabilities = $functioncapabilities;
            $update = true;
        }
        if ($update) {
            $DB->update_record('external_functions', $dbfunction);
        }
    }
    foreach ($functions as $fname => $function) {
        $dbfunction = new stdClass();
        $dbfunction->name = $fname;
        $dbfunction->classname = $function['classname'];
        $dbfunction->methodname = $function['methodname'];
        $dbfunction->classpath = empty($function['classpath']) ? null : $function['classpath'];
        $dbfunction->component = $component;
        $dbfunction->capabilities = key_exists('capabilities', $function) ? $function['capabilities'] : '';
        $dbfunction->id = $DB->insert_record('external_functions', $dbfunction);
    }
    unset($functions);
    // now deal with services
    $dbservices = $DB->get_records('external_services', array('component' => $component));
    foreach ($dbservices as $dbservice) {
        if (empty($services[$dbservice->name])) {
            $DB->delete_records('external_services_functions', array('externalserviceid' => $dbservice->id));
            $DB->delete_records('external_services_users', array('externalserviceid' => $dbservice->id));
            $DB->delete_records('external_services', array('id' => $dbservice->id));
            continue;
        }
        $service = $services[$dbservice->name];
        unset($services[$dbservice->name]);
        $service['enabled'] = empty($service['enabled']) ? 0 : $service['enabled'];
        $service['requiredcapability'] = empty($service['requiredcapability']) ? null : $service['requiredcapability'];
        $service['restrictedusers'] = !isset($service['restrictedusers']) ? 1 : $service['restrictedusers'];
        $update = false;
        if ($dbservice->enabled != $service['enabled']) {
            $dbservice->enabled = $service['enabled'];
            $update = true;
        }
        if ($dbservice->requiredcapability != $service['requiredcapability']) {
            $dbservice->requiredcapability = $service['requiredcapability'];
            $update = true;
        }
        if ($dbservice->restrictedusers != $service['restrictedusers']) {
            $dbservice->restrictedusers = $service['restrictedusers'];
            $update = true;
        }
        if ($update) {
            $DB->update_record('external_services', $dbservice);
        }
        $functions = $DB->get_records('external_services_functions', array('externalserviceid' => $dbservice->id));
        foreach ($functions as $function) {
            $key = array_search($function->functionname, $service['functions']);
            if ($key === false) {
                $DB->delete_records('external_services_functions', array('id' => $function->id));
            } else {
                unset($service['functions'][$key]);
//.........这里部分代码省略.........